Novelty key chain

ABSTRACT

A novelty key chain which comprises a body of transparent rigid material having a bore in one side thereof in the base of which is disposed a first magnet, and a push button slidably disposed in the outer portion of the bore with a second magnet on its inner end, the adjacent ends of the magnets being of like polarity so as to normally maintain the push button in extended position.

iinited States Patent Derby [45] May 23, 1972 [54] NOVELTY KEY CHAIN 2,651,522 9/1953 Steinhardt ..273/160 [72] Inventor: Palmer P. Derby Weston Mass 3,550,936 12/1970 Puttick ..46/236 X [73] Assignee: Raytheon Company, Lexington, Mass. Primal}; Examiner-Innis Mancene Assistant Examiner-D. L. Weinhold [22] Flled 1971 Attorney-Harold A. Murphy, Joseph D. Pannone and Edgar 211 Appl. No.: 131,617 R0st [57] ABSTRACT [52] 11.5. CI. ..35/19A, 46/236 [51] lint. Cl. ..G09b 23/06 A novelty key cham whlch comprises a body of transparent 58 Field of Search ..46/236 45 238 239 35/19 A- rigid material having a in Side hermfin the base 272/4: which is disposed a first magnet, and a push button slidably disposed in the outer portion of the bore with a second magnet 56] References Cited on its inner end, the adjacent ends of the magnets being of like polan'ty so as to normally maintain the push button in ex- UNITED STATES PATENTS tended position- 3,001,106 9/1961 Higgs ..35/l9AX 5Claims,4DrawingFigures NOVELTY KEY CHAIN BACKGROUND OF THE INVENTION Key chains as commonly known are often provided with rigid bodies or supports having attached bead chains, wire loops or the like on which keys may be conveniently carried. While the body part of such devices is sometimes of a useful nature, it is not uncommon to provide bodies which are of little utilitarian value such as puzzles, encased fish lures, name plates or the like. However, such devices do not normally perform a demonstrative function.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a novelty key chain which embodies a body or support part which is operational to perform the function of demonstrating a principle of magnetism. The body embodies a block of transparent material such as glass or plastic. Methyl methacrylate is a particularly suitable material as is clear epoxy.

In one surface of the body is an opening or bore within the base of which is a first magnet which is arranged with the polarity of its poles in known orientation.

Slidable within the bore is a push button having on its inner end a second magnet which is so disposed that its end nearest the first magnet is of a polarity the same as that of the adjacent end of the first magnet. Thus, since like magnetic poles are repulsive, the push button will be normally maintained in extended position. Restriction means such as a lip around the open end of the bore is provided for engaging the second magnet or a portion of the push button to prevent complete withdrawal of the push button.

BRIEF DESCRIPTION OF THE DRAWINGS Reference may be made to the drawings for a complete understanding of the invention and wherein:

FIG. 1 is an isometric view of a preferred form of the inventron;

FIG. 2 is a side elevational view of the device shown in FIG.

FIG. 3 is a front elevational view of the device of FIG. 1 partly in vertical section to show details of the push button in extended position; and

FIG. 4 is a fragmentary sectional view of the push button portion of the device shown in FIG. 3 with the push button depressed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, the invention can be seen as comprising a block of transparent material having any suitable shape. The block 10 is illustrated as a rectangular disc but may be spherical, ovoid, irregular or otherwise of symmetric or asymmetric configuration. The block 10 may be made of plastic such as methyl methacrylate, clear epoxy or the like, or even of glass.

Extending into the body of block 10 from one surface 12 thereof is a bore 14 (FIGS. 3 and 4) in the bottom of which is fixed a first magnet 16. The magnet 16 may be press-fitted or cemented in place as desired so as to be stationary, and is located with its ends or poles in known orientation. The outer end of the bore 14 is enlarged to form a shallow depression in which is sealed a flat ring or collar 18 of annular shape having a central opening 22 which is of a diameter substantially smaller than the diameter of the bore 14. Ring 18 may be of any selected relatively rigid material suitable for retaining a push button within the bore, as will be described, and may be cemented, fused or otherwise mounted in place.

The push button 20 is a rigid member of any suitable material and is of a diameter such as will permit it to easily slide within the aperture 22 longitudinally or axially of the bore 14. The inner end portion 24 of the push button 20 is enlarged so as to engage the inner side of ring 18 and thus prevent the button from sliding out through the aperture 22.

Button portion 24 has cemented to its inner surface a second magnet 26 which slides with portion 18 axially within bore 14 when the push button is depressed and released. However, in accordance with this invention the second magnet 26 is located so that its end or pole nearest the first magnet 16 is of a polarity which is the same as the adjacent pole of the first magnet. Thus, since like magnetic poles repulse or repel], the second magnet 26 and push button are constantly urged in a direction away from the first magnet 16 to the extent permitted by engagement of the enlarged button portion 24 with ring 18.

The magnets 16 and 26 may be of any suitable type but will preferably be of relatively high coercive force such as will resist demagnetization in case the magnets are brought into physical engagement. This could occur if the depth of the bore is so short that depression of the push button 20 will move magnet 26 into engagement with magnet 16. Normally, with low coercive force magnets, such physical contact between the magnets might cause one thereof to become demagnetized with respect to the other, and they will then remain engaged. However, with high coercive force magnets, such demagnetization is resisted, and upon release of the pressure upon the push button the repelling or repulsive magnetic forces will urge the magnets apart and thus move the push button 20 outwardly to a point where portion 24 will engage ring 18.

A particularly good high coercive force magnet is the samarium-cobalt magnet manufactured and sold by Raytheon Company.

Where low coercive force magnets are to be used, it is desirable to dimension the bore 14 so that depression of the push button 20 cannot normally cause the magnets to become physically engaged. In order to do this, the length of the space between magnets 16 and 26 when the push button is extended should be substantially greater than the length of the portion of the push button which extends outwardly from the surface 12 of the block 10. Stated in another way, the effective length of the bore 14 minus the length of magnet 16 should be substantially greater than the overall length of the push button 20 including portion 24 and the magnet 26. This, then, will allow the push button to be depressed, as shown in FIG. 4, to an extent where the exposed end thereof will lie substantially flush with surface 12 of block 10, and it will be seen that a space of substantial size still remains between the magnets 16 and 26.

The above-described function demonstrates the repulsive or repelling characteristics of magnets having adjacent poles of similar polarity. It follows, of course, that the adjacent poles may be either positive or negative.

In order to provide key-retaining characteristics the block 10 may be apertured as indicated at 28 for insertion of a bead chain 30, wire loop, cord or the like on which keys may be suspended.

In accordance with the foregoing it will be apparent that the novelty key chain described will achieve the function of demonstrating the repulsive characteristics of magnets, and will also function as a novel panic button" wherein the push button may be operated to achieve absolutely no operation whatsoever.

It will also be apparent that various modifications may be made by those skilled in the art without departing from the spirit of the invention as expressed in the accompanying claims. I

I claim:

1. A novelty key chain comprising a body of rigid transparent material having a surface with a bore extending therein from said surface, a push button axially slidable within said bore, a movable magnet fixed to the inner end of the push button and slidable therewith within the bore, and a stationary magnet fixed within the bore inwardly from the push button and first magnet, the adjacent ends of the magnets being of like polarity so as to normally maintain the magnets in spaced relation and the push button extended, and means for suspending keys from said body.

2. A novelty key chain as set forth in claim 1 wherein means is provided for preventing complete withdrawal of the push button from the bore.

3. A novelty key chain as set forth in claim 2 wherein said means comprises a stop carried by the body and extending into the open end of the bore, and a projection carried by the push button and located within the bore and adapted to engage said stop when the push button is extended.

4. A novelty key chain as set forth in claim 3 wherein said stop comprises a ring affixed to said surface and encircling the push button, and said projection comprises a circumferential shoulder on the push button.

5. A novelty key chain as set forth in claim 1 wherein stop means is provided for limiting the outward sliding movement of the push button into extended position, and the space between the magnets when the push button is in extended position is greater than the length by which the push button extends beyond said surface. 

1. A novelty key chain comprising a body of rigid transparent material having a surface with a bore extending therein from said surface, a push button axially slidable within said bore, a movable magnet fixed to the inner end of the push button and slidable therewith within the bore, and a stationary magnet fixed within the bore inwardly from the push button and first magnet, the adjacent ends of the magnets being of like polarity so as to normally maintain the magnets in spaced relation and the push button extended, and means for suspending keys from said body.
 2. A novelty key chain as set forth in claim 1 wherein means is provided for preventing complete withdrawal of the push button from the bore.
 3. A novelty key chain as set forth in claim 2 wherein said means comprises a stop carried by the body and extending into the open end of the bore, and a projection carried by the push button and located within the bore and adapted to engage said stop when the push button is extended.
 4. A novelty key chain as set forth in claim 3 wherein said stop comprises a ring affixed to said surface and encircling the push button, and said projection comprises a circumferential shoulder on the push button.
 5. A novelty key chain as set forth in claim 1 wherein stop means is provided for limiting the outward sliding movement of the push button into extended position, and the space between the magnets when the push button is in extended position is greater than the length by which the push button extends beyond said surface. 